Power-driven toothbrush with lip guard



Oct. 20, 1953 D. P. GROVER 2,655,675

POWER-DRIVEN TOOTHBRUSH WITH LIP GUARD Filed Oct. 10, 1946 2Sheets-Sheet 1 INVENTOR. DONALD E GROVER' BY Mam/z 72 Oct. 20, 1953 D.P. GROVER POWER-DRIVEN TOOTHBRUSH WITH LIP GUARD 2 Sheets-Sheet 2 FiledOct. 10, 1946 FIGJZ JNVENTOR. DONALD P. GROVER BY ATT Ys Patented Oct.20, 1953 POWER-DRIVEN TOOTHBRUSH WITH LIP GUARD Donald P. Grover.Chicago, 11].

Application October 10, 1946, Serial No. 702,535

6 Claims. 1

This invention relates in general to power driven toothbrushes and inparticular to a type of rotary toothbrush adapted for personal use, asdistinguished from those commonly used by dentists.

Various forms of rotary or mechanical toothbrushes have been developedheretofore, but have found very little favor with the public in general.One of the disadvantages of the early type of rotary toothbrush was theabsence of any shield partially surrounding the brush element, thuscausing some of the toothpaste on the brush to be thrown off andsplattered about during the rotation of the brush and permitting thebrush to contact the soft inner portions of the mouth causing irritationthereof.

A later development introduced a shield which extended lengthwise of andpartially surrounded the rotating brush element to prevent suchsplattering and mouth irritation. However, actual useage of this type ofbrush proved unsatisfactory because of the tendency of the lip of theuser to be drawn inwardly by the bristles of the brush and between thebristles and the edge of the shield when the brush was placed againstthe teeth, causing laceration and irritation.

All of these earlier toothbrushes contained but a single brush elementand since it is considered a important by dentists that the proper wayto brush teeth is away from the gums, it has been necessary to providesome reversing mechanism in order to reverse the direction of rotationof the single brush element when cleaning upper and lower teeth. Theterminology referring to cleaning or brushing the teeth away from thegums, as used herein, is intended to convey the meaning that thebrushing begins on or close to the gums and moves away from the gumstoward the biting surface of the teeth.

I have been able to overcome the disadvantages of these earlier types ofrotary toothbrushes in my present invention, the principal object ofwhich is to provide an electrically or mechanically driven toothbrushhaving a plurality of brush elements whereby the teeth of a user may beplaced therebetween and thus simultaneously brush and clean the frontand back sides thereof.

Another object of the invention is to provide a rotary toothbrushwherein at least two brush elements are provided to receive the teeth ofa user therebetween and to rotate these brush elements toward each otherin opposite directions away from the gums to insure simultaneouscleaning of the inner and outer surfaces of the teeth.

Still another object is to provide a rotary toothbrush having aplurality of rotatable brush elements wherein novel lip guards arelocated adjac nt to on r both s des f ach brush die 2 ment to preventthe lip or other soft fleshy portions of the inside of'the mouth of auser from being drawn inwardly between the bristles and the shield,which would cause laceration and irritation. A still further object isto provide novel driving means for simultaneously driving the brushelements in opposite directions. Another and still more specific objectof the invention is to provide a rotary toothbrush wherein a pair ofbrush elements are mounted on a handle portion or a head providedtherefor in substantially parallel relation to the handle portion,whereby the teeth of a user may be placed between the brush elements forsimultaneously cleaning the front and rear sides thereof. Other objectsand advantages of the invention will become apparent upon reading thefollowing description taken in connection with the accompanying drawingsin which: i Fig. 1 is a longitudinal horizontal section through one formof the device of the present invention;

Fig. 2 is a vertical longitudinal section taken substantially along theplane of line 2--2 of Fig. 1; Fig. 3 is a vertical transverse sectiontaken substantially along the plane of line 33 of Fig. 1;

Fig. 4 is a fragmentary longitudinal section substantially along theplane of line 44 of Fig. 1;

Fig. 5 is a vertical transverse section taken substantially along theplane of line 55 of Fig. 1;'

. Fig. 6 is a transverse section taken substantially along the plane ofline 6-6 of Fig. 1;

. Fig. 7 is a transverse section taken substantially along the plane ofline !1 of Fig. 1;

' Fig. 8 is a vertical section through the cheek and molars of a usershowing the device of this invention in one position thereof for use;

Fig. 9 is a view similar to Fig. 8 but showing the device in a differentposition for use;

Fig. 10 is a view similar to Figs. 8 and 9 showing still a thirdposition of the device in use;

Fig. 11 is a longitudinal sectional view through a modified form of thedevice showing a different driving mechanism;

Fig. 12 is a fragmentary longitudinal section through one end of thedevice showing a still further modified form of driving mechanism;

Fig. 13 is an exploded view of the driving elements shown in Fig. 12.

The present invention contemplates the use of a plurality of brushelements which are adapted to rotate, or to which any other suitablemotion may be imparted which can be adapted to clean the teeth of a userwhen placed thereagainst. The device illustrated herein is similar insome respects, particularly as to the plurality of brushes, with thedevice shown in my copending application bearing Serial No. 700,315filed September 30, 1946. In my said co-pending application the brushelements have been i1- lustrated as being located at right angles to thehandle portion, whereas in the present :invention they are illustratedas being parallel thereto. My above referred to application alsodiscloses the use of four brush elements and it is considered within thepurviewof the present invention that more than the two brush elementscan also be used without departing from the spirit of the invention.

Also illustrated herein are various forms of lip guards, all of whichhavebeen disclosed for use on a single brush :device in one or more ofmy earlier filed oo-pending applications, Ser. Nos. 691,273 now PatentNo. 2,533,106; 691;979 now Patent No. 2,533,107; and 692,270 nowPatentNo. 2,533,108, which were filed respectively on August 17, 1946, August21, 1946, and August 22, 1946, and all of said patents having beenissued on December 5, 1950.

Referring now more particularly to the drawlugs and especially to Figs.1 through 10, I have shown the device as inchidi-ng a handle portion Iwhich may be formed of any suitable material or combination ofmaterials, which terminates at one end thereof in a slightly enlargedsection which may be termed a head 2.

The head may be divided into a pair of cavities or elongated recesses 3and 4 having a partition 5 therebetween. A brush element having aspindle 6 and bristles 1 extending radially therefrom is adapted to belocated in one of the cavities, while a similar brush element islikewise mounted in the other cavity. The head is provided with a bottomor lower side 8 and an upwardly extending forward end 9 adapted toreceive bearing members I0 and II Within which one end of the spindles 6may be mounted for rotation.

The handle portion l is so made as to permit a pair of driving shafts I2and 13 to extend longitudinally therethrough. The forward end of eachshaft is mounted in a bearing [4 and is provided with a transverselyextending slot into which a transverse rib 15 on the opposite end ofeach brush spindle may be received. This construction then forms acoupling so that rotation of either or both of the shafts l2 and II willim part of rotative movement to the brush element connected thereto.

The driving means for this device may be any suitable mechanism and mayinclude an electric motor as an integral part of the handle or mayembody a flexible shaft connected to a suitable source of rotationalmovement. It is more desirable and presents fewer problem in themanufacture of the device itself if such a flexible shaft is used. Inthe construction as illustrated in Fig. 1 the rear end of the handleportion is provided with a pair of openings l6 extending inwardly andadapted to receive the shafts l2 and 13. This opening i slightly largerthan the one which extends the full length of the shaft to permit aretaining ring I! to surround an annular groove I8 in each shaft tolimit the longitudinal movement thereof. A hearing member I9 is locatedin each of the openings l8 and is adapted to rotatably mount the end ofeach of the driving shafts. It will thus be evident that the retainingrings I 1 will bear against the shoulwhen the connection is made, theshafts are caused to rotate, thus driving the brushes.

When it is desired to remove the brush elements such as for cleaning orreplacement, the shafts 1'2 and I3 may be moved rearwardly until theretaining rings H bear against the inner ends of the bearings ISI. Thiswill be suflicient to give clearance to the brush element spindles andpermit removal thereof.

Any suitable lip guards :may be provided such as those disclosed .in myabove referred to copending applications, but the preferred form is thatas shown in Fig. 1 where the central dividing partition 5 has aplurality of outwardly extending :partitions or teeth 2|. These teethare spaced apart along :the length of each brush element to permit thebristles thereof to extend therebetween. Thus no impairment of thecleaning-qualties of the-brush will occur. On the other hand the lipguards are'advantageous and highly desirable in that they prevent thesoft mouth parts, such as lips, tongue, and other soft fleshy portionsof a user from being drawn inwardly by the rotating brush elements andthereagainst thus causing irritation and lacerations as above explained.

Figs. 8, -9 and 10 illustrate a typical use of this type of rotarytoothbrush. The positions of the brush elements shown herein will beequally applicable regardless of the angular position of the two brushelements with respect to the handle portion. For example, the positionsshown in these figures would be the same if the brush elements extendedtransversely of the handle portion as shown in my coepending applicationfirst above referred to.

In these figures the mouth of a user may be generally indicated by thenumeral 22 wherein upper teeth 23 and lower teeth 24 are shown. Also,the tongue is indicated at 25. In Fig. 8 the brush elements are shown asrotating simultaneously in opposite directions toward each other so thatthe bristles of the outer brush element will begin to clean on the upperoutside gum 26 and will finish the cleaning motion on the outer surfaceof the teeth 23. At the same time the other brush element is cleaningthe inner surface of the teeth.

In Fig. 9 the inner brush element is shown as beginning its cleaningmovement on the inner gum portion 21 and finishing the cleaning motionon the inner surface of the tooth itself. The shield 8 has upwardlycurved sides partially surrounding the brush elements and the functionthereof, to prevent the tongue and cheek from being irritated by therotating bristles, is clearly indicated in these figures.

In Fig. 10 the brush elements are shown in a position where one iscleaning the biting surface of the upper teeth and the other isoperating in a cleaning movement downwardly, beginning on the insideupper gum. The operation will be identical for cleaning the lower teethand the lip guard on the opposite side will then function to prevent thetongue and inside of the check or lips from becoming irritated in thesame manner as described above.

While it will be evident that the brush elements can be rotated eitheralternately or simultaneously and can be moved in the same or oppositedirections, it has been considered the best practice from a hygienicstandpoint that these brushes rotate in such a way as to clean the teethaway from the gums, and the manner of cleaning as illustrated in Figs.8, 9 and 10 indicates the brush elements as rotating in this manner.

Fig. 11 discloses a modified form of drive mechanism wherein the handle42 can be made smaller to permit two small flexible shafts 43 and 44 tobe inserted therein. The handle 42 may be provided with a similar head45 which has the cavities or recesses 46 and 4'1 therein and the lipguards 48. The spindles of the brush elements are indicated at 49 and5i] and the bristles thereof have been omitted from this view in orderto more clearly show the construction thereof.

The outer ends of the spindles 49 and 50 may be suitably received inbearings 5| and 52, while the inner ends thereof are provided with thetransversely extending ribs 53 and '54 which are adapted to be receivedin suitable recesses in the portion 55 of a universal jointconstruction. The other portion 55 of the universal joint in each caseis adapted to rotate in suitable bearings within the handle portion andare connected to the ends of the flexible shafts 43 and 44. One of theseflexible shafts, for example 44, may have a suitable gear 51 mounted onone end thereof adapted to be in mesh with a similar gear 58 on theshaft 43. The shaft 43 then continues as at 59 and terminates in asuitable connection 60 for purposes of connecting to a source of powerfor rotating the various shafts. This form of the invention permits theuse of a smaller handle portion, but also causes the brush elements tofunction in their normal manner by simultaneously rotating in oppositedirections toward each other for cleaning the teeth.

The drive mechanism disclosed in Figs. 12 and 13 is a modified form ofthat shown in Fig. 11 wherein the handle portion 6| can also be madeconsiderably smaller because of the fact that a single shaft 62 extendstherethrough and is adapted to rotate the spindles 63 and 64 of thebrush elements preferably in opposite directions. The head 65 may besimilar to that shown in Fig. 11 and the brush elements may be mountedtherein in the same way. In this form of driving means the shaft 62 isprovided at its inner end with a bevel gear 66 which is adapted to be inmesh with a bevel gear '61 located at right angles thereto and mountedon a transversely extending shaft as. Other forms of gearing could beused with equal success, for example worm gears, if so desired.

The ends of the shaft 58 are provided with reversely positioned wormsections 69 and 1'0 which are in mesh with worm gears H and I2repectively mounted on the stub shafts 13 and 14. The outer ends ofthese stub shafts are provided with transversely extending slots adaptedto receive the ribs extending transversely of the inner ends of thespindles 53 and 64. Thus it will be evident that upon rotation of theshaft 632 it will cause a rotation of the transverse shaft 68 throughthe medium of the bevel gears, which will in turn rotate the spindles 63and 64 in 0pposite directions through the worm and worm gear arrangementjust described.

From the foregoing description it will be evident that I have provided anovel type of multiple headed rotary toothbrush, which may bedistinguished from my earlier filed co-pendin application first abovereferred to by positioning the brush elements in pairs extendinglongitudinally of the handle portion. The advantages of the varioustypes of lip guards and driving means over those disclosed in the priorart, will be apparent to those skilled in the art. It will be evidentthat certain changes may be made in the form, construction andarrangement of parts from those disclosed herein without in any waydeparting from the spirit of the invention or sacrificing any of theattendant advantages thereof, provided, however, that such changes fallwithin the scope of the claims appended hereto.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent of the United States is:

l. A power driven toothbrush of the class described, comprising a handleportion having a head at one end thereof, a pair of substantiallyparallel cavities in said head extending lengthwise of said handleportion and having a partition therebetween, a brush element in each ofsaid cavities, means for rotatably mounting a brush element in each ofsaid cavities, and lip guards integral with said partition and extendinggenerally radially outwardly therefrom toward both brush elements tothereby prevent the lip of a user from being injured.

2. A power driven toothbrush of the class described, comprising a handleportion, a pair of elongated brush elements rotatably mounted thereon inparallel relation thereto, a single shaft extending through said handleportion, a

- gear train connecting said shaft with said brush elements, wherebyrotation of said shaft will rotate said brush elements in oppositedirections, guard supporting means positioned longitudinally betweensaid brush elements, and guard means on said supporting means disposedbetween said brush elements and extending substantially radiallyoutward-1y toward both of said brush elements and terminating short ofthe axes of said brush elements to prevent portions of the mouth of auser from being drawn inwardly between the brush elements.

3. A power driven toothbrush of the class described comprising anelongated handle, a pair of brushes substantially circular in crosssection, means for removably and rotatably mounting said brushes on saidhandle in side by side spaced parallelism with the axes of rotationthereof substantially parallel with the axis of said handle, anelongated lip guard supporting member disposed between said brushes anddisposed substantially parallel with the axes thereof, and guard meansmounted on said supporting member and confined within the space betweenthe axes of said brushes to prevent portions of the mouth of a user frombeing drawn inwardly between said brushes.

4. A power driven toothbrush of the class described comprising anelongated handle, a pair of brushes substantially circular in crosssection, means for removably and rotatably mounting said brushes on saidhandle in side by side spaced parallelism with the axes of rotationthereof substantially parallel with the axis of said handle, anelongated lip guard supporting member disposed between said brushes anddisposed substantially parallel with the axes thereof, and guard meansmounted on said supporting member and extending outwardly therefromtoward both of said brushes and terminatin short of the axes of saidbrushes to prevent p01- tknsoithe mouths! e userirom being drawninwardly between said brushes.

5 A power driven toothbrush of the class described comprislnx anelongated handle, a. pair of brushes substantially circular in crosssection, means for .removahly and rotatably mountin: said brushes onsaid handle in side by side p ed parallelism with the axes of rotationthereof substantially parallel with the axis of said handle. and aplurality of guard members 10 between said brushes spaced apart alongthe length thereof and confined entirely to the space between the axesof the brushes to prevent portions of the mouth of a user from beingdrawn inwardly between said brushes.

.6. A power driven toothbrush of the class described comprising 1melongated hand-1e, a pair or brushes substantially eireular in crosssection, means for rotatably mounting said brushes on said handle inside by sid spa d p r ism with the axes of r tation thereofsubstantially parallel with the axis of said handle, and a plurality ofguard members between said brushes spaced apart alon the length thereofand confined within the space between the axes of the brushes to preventportions of the mouth of a user 1mm being drawn winwardly between saidbrushes.

DONALD P. GROVER.

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